The main techniques for the production of polymer nanofibres comprise processes of extrusion of a polymer melt through holes of nanometric dimensions in a template and processes of electrospinning. Electrospinning involves the use of a source of high voltage for generating electrically charged polymer jets, which are collected on a substrate as a mat of nanofibres. This technique requires the polymer to be processable in the liquid state and to be able to withstand high voltage.
In practice, however, these known techniques are not applicable for the production of nanofibres polymerized from cyanoacrylate monomers, commonly known as “Super Glue®” or “Super Attak®”. The property of these monomers of polymerizing instantaneously and irreversibly in the presence of moisture in fact makes the electrospinning process rather difficult. The polymerization of the monomer triggered by the humidity of the air in fact causes obstruction of the point of the needles during processing. Moreover, the product collected on the target substrate is generally in the form of drops or beads that are not suitable for electrospinning.
Some very recent works that dealt with the problems relating to the production of poly(cyanoacrylate) nanofibres proposed, as the only existing method available for producing such nanofibres, the condensation of vapours of cyanoacrylate on specially conditioned and structured surfaces.
In contact with such surfaces, the monomers polymerize in the form of fibrillar network structures of micrometric or nanometric dimensions [1-3].
For example, fingerprints left on surfaces can act as sites of initiation for vapours of cyanoacrylate monomer and polymerization follows the thin lines of the fingerprints, forming poly(cyanoacrylate) fibres. However, the main disadvantages of these approaches concern the difficulty of scale-up and lack of process control during moisture-activated polymerization, which leads to a crosslinked polymer structure that is in the form of a hard white solid.
In this state, crosslinked cyanoacrylates cannot be dispersed in common solvents in order to be used as polymer solutions.